Triazolopyridine dyes and thermal transfer of methine dyes

ABSTRACT

Triazolopyridine dyes useful for thermal transfer of methine dyes have the formula ##STR1## where R 1  is C 1  -C 20  -alkyl, which may be substituted and interrupted by one or more oxygen atoms, or is substituted or unsubstituted phenyl or hydroxyl, 
     R 2  is a 5- or 6-membered carbocyclic or heterocyclic ring which may be substituted and benzofused, 
     R 3  is cyano, carbamoyl, carboxyl or C 1  -C 4  -alkoxycarbonyl, 
     R 4  is oxygen or a radical of the formula ##STR2##  where L 1  is in each case C 1  -C 8  -alkyl which may be interrupted by 1 or 2 oxygen atoms, and 
     X is CH or nitrogen.

This is a division of application Ser. No. 07/569,914, filed on Aug. 20, 1990, now U.S. Pat. No. 5,079,365.

The present invention relates to novel triazolopyridine dyes of the formula I ##STR3## where R¹ is C₁ -C₂₀ -alkyl, which may be substituted and interrupted by one or more oxygen atoms, or is substituted or unsubstituted phenyl or hydroxyl,

R² is a 5- or 6-membered carbocyclic or heterocyclic ring which may be substituted and benzo fused,

R³ is cyano, carbamoyl, carboxyl or C₁ -C₄ -alkoxycarbonyl,

R⁴ is oxygen or a radical of the formula ##STR4## where L¹ is in each case C₁ -C₈ -alkyl which may be interrupted by 1 or 2 oxygen atoms, and

X is CH or nitrogen, and to a process for the thermal transfer of methine dyes.

U.S. Pat. No. 4,769,360 discloses benzoquinoneimine dyes which are derived from p-phenylenediamine derivatives and are said to be suitable for thermal transfer printing. However, it has been found that these dyes have inadequate coloristic properties.

It is an object of the present invention to provide new dyes which are advantageous for the thermal transfer process.

We have found that this object is achieved by the triazolopyridine dyes of the formula I defined at the beginning.

The dyes of the formula I can exist in multiple tautomeric forms which are all encompassed by the claim. For example, compounds where R⁴ is oxygen can exist inter alia in the following tautomeric forms: ##STR5##

When R¹ in the formula I is substituted C₁ -C₂₀ -alkyl, possible substituents are for example phenyl, C₁ -C₄ -alkylphenyl, C₁ -C₄ -alkoxyphenyl, halophenyl, C₁ -C₈ -alkanoyloxy, C₁ -C₂₀ -alkoxycarbonyl, C₁ -C₂₀ -alkoxycarbonyloxy, the alkyl chains of the two last-mentioned radicals being optionally interrupted by from 1 to 4 oxygen atoms and/or phenyl- or phenoxy-substituted, halogen, hydroxyl and cyano.

When R¹ in the formula I is alkyl interrupted by oxygen atoms, preference is given to those alkyl radicals which are interrupted by from 1 to 4 oxygen atoms, in particular by 1 or 2 oxygen atoms.

When R¹ in the formula I is substituted phenyl, possible substituents are for example C₁ -C₈ -alkyl, C₁ -C₈ -alkoxy, halogen, in particular chlorine or bromine, and carboxyl.

R² can be derived for example from the components of the benzene, indole, quinoline, aminonaphthalene, pyrrole, aminothiazole, benzimidazole, benzothiazole, aminothiophene or diaminopyridine series.

Important radicals R² are for example those of the formulae IIa to IIu ##STR6## where n is 0 to 1,

L² and L³ are identical or different and each is independently of the other hydrogen or the abovementioned radical R¹,

R⁵ and R⁶ are identical or different and each is independently of the other hydrogen, hydroxyl, unsubstituted or phenyl- or C₁ -C₄ -alkylphenyl-substituted C₁ -C₈ -alkyl, unsubstituted or phenyl- or C₁ -C₄ -alkylphenyl-substituted C₁ -C₈ -alkoxy, C₁ -C₈ -alkanoylamino, C₁ -C₈ -alkylsulfonylamino or C₁ -C₈ -monoalkylaminosulfonylamino or -dialkylaminosulfonylamino,

R⁷ is hydrogen or methyl,

R⁸ is hydrogen, halogen, C₁ -C₈ -alkyl, unsubstituted or C₁ -C₄ -alkyl- or C₁ -C₄ -alkoxy-substituted phenyl, unsubstituted or C₁ -C₄ -alkyl- or C₁ -C₄ -alkoxy-substituted benzyl, cyclohexyl, thienyl, hydroxyl or C₁ -C₈ -monoalkylamino,

R⁹ is cyano, carbamoyl, C₁ -C₈ -monoalkylcarbamoyl or -dialkylcarbamoyl or C₁ -C₈ -alkoxycarbonyl, and

R¹⁰ is halogen, hydrogen, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy, C₁ -C₄ -alkylthio or unsubstituted or C₁ -C₄ -alkyl-substituted phenyl.

Any alkyl appearing in the abovementioned formulae is either straight-chain or branched.

R¹, R⁵, R⁶, R⁸, R¹⁰, L¹ and L² are each for example methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl or tert-butyl.

R¹, R⁵, R⁶, R⁸, L¹ and L² may each also be for example pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, 2-methylpentyl, heptyl, 1-ethylpentyl, octyl, 2-ethyl-hexyl or isooctyl.

R¹ may also be for example nonyl, isononyl, decyl, isodecyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl (the designations isooctyl, isononyl, isodecyl and isotridecyl are trivial names which are derived from the alcohols obtained by the oxo process--cf. on this point Ullmanns Encyklopaadie der technischen Chemie, 4th edition, volume 7, pages 215 to 217, and volume 11, pages 435 and 436).

R¹, L¹ and L² may each also be for example 2-methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-isopropoxyethyl, 2-butoxyethyl, 2- or 3-methoxypropyl, 2- or 3-ethoxypropyl, 2- or 3-propoxypropyl, 2- or 3-butoxypropyl, 2- or 4-methoxybutyl, 2- or 4-ethoxybutyl, 2- or 4™propoxybutyl, 3,6™dioxaheptyl, 3,6-dioxaoctyl, 4,8-dioxanonyl, 3,7-dioxaoctyl, 3,7-dioxanonyl, 4,7-dioxaoctyl, 4,7-dioxanonyl, 2- or 4-butoxybutyl or 4,8-dioxadecyl.

R¹ may also be for example 3,6,9-trioxadecyl, 3,6,9-trioxaundecyl 3,6,9,12-tetraoxatridecyl 3,6,9,12-tetraoxatetradecyl, 2-carboxyethyl, 2-methoxycarbonylethyl, benzyl, 1- or 2-phenylethyl, 3-benzyloxypropyl, phenoxymethyl, 6-phenoxy-4-oxahexyl, 8-phenoxy-4-oxaoctyl, 2-, 3- or 4-chlorophenyl or 2-, 3- or 4-carboxylphenyl.

R³ and R⁹ are each for example methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl or sec-butoxycarbonyl.

R⁹ may also be for example mono- or di-methylcarbamoyl, mono- or diethylcarbamoyl, mono- or dipropylcarbamoyl, mono- or diisopropylcarbamoyl, mono- or dibutylcarbamoyl or N-methyl-N-butylcarbamoyl.

R⁵, R⁶ and R¹⁰ may each also be for example methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy or sec-butoxy.

R¹⁰ may also be for example methylthio, ethylthio, propylthio, isopropylthio, butylthio, isobutylthio or sec-butylthio.

R¹, R⁸ and R¹⁰ may each also be for example phenyl, 2-, 3- or 4-methylphenyl, 2-, 3- or 4-ethylphenyl, 2-, 3-or 4-propylphenyl, 2-, 3- or 4-isopropylphenyl, 2-, 3- or 4-butylphenyl or 2,4-dimethylphenyl.

R¹ and R⁸ may each also be for example 2-, 3- or 4-methoxyphenyl, 2-, 3- or 4-ethoxyphenyl, 2-, 3- or 4-isobutoxyphenyl or 2,4-dimethoxyphenyl.

R¹ may also be for example 2-cyanoethyl, 4-cyanobutyl, 2-hydroxyethyl, 5-hydroxynonyl or a radical of the formula ##STR7##

Preference is given to triazolopyridine dyes of the formula I where R³ is cyano.

Preference is also given to triazolopyridine dyes of the formula I where R² is derived from a component of the benzene, indole, quinoline, aminonaphthalene, pyrrole, aminothiazole, benzimidazole, benzothiazole, aminothiophene or diaminopyridine series.

Preference is also given to triazolopyridine dyes of the formula I where R¹ is C₁ -C₁₂ -alkyl, which may be substituted by C₁ -C₆ -alkanoyloxy, C₁ -C₈ -alkoxycarbonyl (whose alkyl chains may each be interrupted by 1 or 2 oxygen atoms), phenyl or C₁ -C₄ -alkylphenyl and interrupted by 1 or 2 oxygen atoms.

Particular preference is given to triazolopyridine dyes of the formula I where R¹ is alkyl, alkoxyalkyl, alkanoyloxyalkyl or alkoxycarbonylalkyl, which may each have up to 12 carbon atoms, or is unsubstituted or methyl-substituted benzyl or unsubstituted or methyl-substituted phenyl.

Particular preference is also given to triazolopyridine dyes of the formula I where R² is a radical of the abovementioned formula IIa, IIc, IIk, IIl, IIm or IIn, where

L² and L³ are each independently of the other alkyl, alkoxyalkyl, alkanoyloxyalkyl or alkoxycarbonylalkyl, which may each have up to 12 carbon atoms, or hydrogen, unsubstituted or methyl-substituted benzyl or unsubstituted or methyl-substituted phenyl,

R⁵ and R⁶ are each independently of the other hydrogen, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy or C₁ -C₈ -alkanoylamino, and

R⁸ is hydrogen, C₁ -C₄ -alkyl, unsubstituted or C₁ -C₄ -alkyl- or C₁ -C₄ -alkoxy-substituted phenyl, benzyl or thienyl.

The dyes of the formula I according to the present invention can be prepared in a conventional manner.

For instance, those triazolopyridine dyes of the formula I where X is CH can be obtained by condensing aldehydes of the formula III

    R.sup.2 --CHO                                              (III),

where R² is as defined above, with triazolopyridines of the formula IV ##STR8## where R¹, R³ and R⁴ are each as defined above.

Those triazolopyridine dyes of the formula I where X is nitrogen can be obtained for example by condensing the nitroso compounds of the formula V

    R.sup.2 --NO                                               (V),

where R² is as defined above, or by oxidative coupling of the amino compounds of the formula VI

    R.sup.2 --NH.sub.2                                         (VI),

where R² is as defined above, with the triazolopyridines IV.

The triazolopyridines of the formula IV are likewise compounds known per se. Their preparation is described for example in earlier German Patent Application P 39 26 770.9.

It is a further object of the present invention to provide a process for the thermal transfer of dyes, a process wherein the dyes used should ideally have no application defects.

In the thermal transfer printing process, a transfer sheet which contains a thermally transferable dye in one or more binders, with or without suitable assistants, on a substrate is heated from the back with an energy source, for example a thermal printing head, in short heating pulses (duration: fractions of a second), as a result of which the dye migrates out of the transfer sheet and diffuses into the surface coating of a receiving medium. The essential advantage of this process is that the amount of dye to be transferred (and hence the color gradation) is easy to control by adjusting the energy supply to the heat source.

In general, color recording is carried out using the three subtractive primaries yellow, magenta and cyan (with or without black). To ensure optimal color recording, the dyes must have the following properties:

ready thermal transferability,

little tendency to migrate within or out of the surface coating of the receiving medium at room temperature,

high thermal and photochemical stability and also resistance to moisture and chemical substances,

suitable hues for subtractive color mixing,

a high molar absorption coefficient,

resistance to crystallization on storage of the transfer sheet,

ready industrial availability.

Experience shows that these requirements are very difficult to meet all at once.

For this reason most of the existing thermal transfer printing dyes fall short of the postulated ideal.

We have found that the object is achieved, and that the transfer of methine dyes by diffusion from a transfer to plastic-coated paper with the aid of an energy source is possible to advantageous effect, on using a transfer on which there is or are situated one or more dyes of the formula I and/or Ia ##STR9## where R¹ is C₁ -C₂₀ -alkyl, which may be substituted and interrupted by one or more oxygen atoms, or is substituted or unsubstituted phenyl or hydroxyl,

R² is a 5- or 6-membered carbocyclic or heterocyclic ring which may be substituted and benzo fused,

R³ is cyano, carbamoyl, carboxyl or C₁ -C₄ -alkoxycarbonyl,

R⁴ is oxygen or a radical of the formula ##STR10## where L¹ is in each case C₁ -C₈ -alkyl which may be interrupted by 1 or 2 oxygen atoms, and

X is CH or nitrogen.

A suitable energy source for the transfer of the dyes of the formula I and/or Ia by diffusion is for example a thermal printing head or a laser. The use of a thermal printing head is preferred.

Preference is given to the process involving the transfer of dyes of the formula I.

Preference is further given to the process involving the transfer of triazolopyridine dyes of the formula I where R³ is cyano.

Preference is further given to the process involving the transfer of triazolopyridine dyes of the formula I where R² is derived from a component of the benzene, indole, quinoline, aminonaphthalene, pyrrole, aminothiazole, benzimidazole, benzothiazole, aminothiophene or diaminopyridine series.

Preference is further given to the process involving the transfer of triazolopyridine dyes of the formula I where R¹ is C₁ -C₁₂ -alkyl, which may be substituted by C₁ -C₆ -alkanoyloxy, C₁ -C₈ -alkoxycarbonyl (whose alkyl chains may each be interrupted by 1 or 2 oxygen atoms), phenyl or C₁ -C₄ -alkylphenyl and interrupted by 1 or 2 oxygen atoms.

Particular preference is given to the process involving the transfer of triazolopyridine dyes of the formula I where R¹ is alkyl, alkoxyalkyl, alkanoyloxyalkyl or alkoxycarbonylalkyl, which may each have up to 12 carbon atoms, or is unsubstituted or methyl-substituted benzyl or unsubstituted or methyl-substituted phenyl.

Particular preference is further given to the process involving the transfer of triazolopyridine dyes of the formula I where R² is a radical of the abovementioned formula IIa, IIc, IIk, IIl, IIm or IIn, where

L² and L³ are each independently of the other alkyl, alkoxyalkyl, alkanoyloxyalkyl or alkoxycarbonyl-alkyl, which may each have up to 12 carbon atoms, or hydrogen, unsubstituted or methyl-substituted benzyl or unsubstituted or methyl-substituted phenyl,

R⁵ and R⁶ are each independently of the other hydrogen, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy or C₁ -C₈ -alkanoylamino, and

R⁸ is hydrogen, C₁ -C₄ -alkyl, unsubstituted or C₁ -C₄ -alkyl- or C₁ -C₄ -alkoxy-substituted phenyl, benzyl or thienyl.

To prepare the transfer required for the process, the dyes are incorporated into suitable organic solvents, e.g. chlorobenzene, isobutanol, methyl ethyl ketone, methylene chloride, toluene, tetrahydrofuran or a mixture thereof, together with one or more binders and with or without the addition of other auxiliaries, to form a printing ink. It preferably contains the dye in a molecularly dispersed, i.e. dissolved, form. The printing ink is applied to the inert substrate by knife coating and the coating is dried in air. A suitable binder is any resin or polymer material which is soluble in organic solvents and capable of binding the dye to the inert substrate in such a way that it will not rub off. Preference here is given to those binders which, after the printing ink has dried in air, hold the dye in the form of a clear, transparent film without visible crystallization of the dye.

Examples of such binders are cellulose derivatives, e.g. methylcellulose, ethylcellulose, ethylhydroxyethylcellulose, hydroxypropylcellulose, cellulose acetate or cellulose acetobutyrate, starch, alginates, allyl resins, vinyl resins, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyrate and polyvinylpyrrolidones. It is also possible to use polymers and copolymers of acrylates or derivatives thereof, such as polyacrylic acid, polymethyl methacrylate or styrene-acrylate copolymers, polyester resins, polyamide resins, polyurethane resins or natural CH resins, such as gum arabic. Other suitable binders are described for example in DE-A-3 524 519.

The preferred binders are ethylcellulose, ethylhydroxyethylcellulose, polyvinyl butyrate and polyvinyl acetate.

The ratio of binder to dye is preferably within the range from 1:1 to 5:1 by weight.

Suitable assistants are for example release agents as described in EP-A-227 092, EP-A-192 435 and the patent applications cited therein and also in particular organic additives which stop the transfer dye from crystallizing in the course of storage or heating of the inked ribbon, for example cholesterol or vanillin.

Inert substrates are for example tissue, blotting or parchment paper or plastics films of high heat stability, for example uncoated or metal-coated polyester, polyamide or polyimide. The inert substrate may additionally be coated on the side facing the energy source with a lubricant, or slipping, layer in order to prevent adhesion of the energy source to the substrate material. Suitable lubricants are described for example in EP-A-216 483 and EP-A-227 095. The thickness of the substrate is in general from 3 to 30 μm, preferably from 5 to 10 μm.

Suitable dye receiver layers are basically all temperature stable plastic layers having an affinity for the dyes to be transferred and preferably glass transition temperatures (Tg) within the range 50° C.<Tg<100° C., e.g. modified polycarbonates and polyesters. Suitable recipes for the receiver layer composition are described in detail for example in EP-A-227 094, EP-A-133 012, EP-A-133 011, EP-A-111 004, JP-A-199 997/1986, JP-A-283 595/1986, JP-A-237 694/1986 and JP-A-127 392/1986.

Transfer is preferably effected, as described above, by means of a thermal printing head which must be heatable to ≧300° C. for dye transfer to take place within the time interval t: 0<t<15 msec. On heating, the dye migrates out of the transfer sheet and diffuses into the surface coating of the receiving medium.

Compared with the dyes used in existing processes, the novel dyes transferred in the process according to the present invention are in general notable for improved migration properties in the receiving medium at room temperature, readier thermal transferability, readier industrial availability, better resistance to moisture and chemical substances, higher color strength, better solubility, higher thermal and photochemical stability and in particular better purity of hue.

The purity of hue results from the steeper slope of the main absorption band and from the higher transparency in blue and green regions.

The novel dyes give complete coverage of the range from red to turquoise. Of particular interest here are magenta and cyan dyes which, owing to their remarkable brilliance, are suitable as primaries for subtractive color mixing.

Details concerning the preparation are given in the examples, in which percentages are by weight, unless otherwise stated.

The examples which follow illustrate the invention. Preparation of the dyes ##STR11##

11 g of N,N-dibutyl-m-toluidine were nitrosated with sodium nitrite at 0° C. to 5° C. in aqueous hydrochloric acid. After 2 hours the mixture was rendered alkaline with 25% strength ammonia at 0°-10° C. and extracted with 150 ml of methylene chloride. The organic phase was then added with stirring to a suspension of 13.6 g of the compound of the formula ##STR12## in acetic anhydride at room temperature. The reaction began immediately to give a slightly exothermic response (32° C.). The mixture was subsequently stirred at room temperature for a further 2 hours, heated to 40° C. and admixed with water to hydrolyse the acetic anhydride. The organic phase was extracted three times with water in a separating funnel and concentrated in a rotary evaporator. The residue was suspended in water, the suspension was neutralized with bicarbonate solution and filtered with suction, and the filter residue was washed until neutral and dried at room temperature.

Yield: 23.3 g=92% of theory

Melting point: 147° C.

λ_(max) (THF): 615 nm

R_(f) : 0.60 (8:2 toluene/ethyl acetate).

Example Pl was also followed to prepare the following dyes by in each case distilling off all the methylene chloride and carrying out the reaction at 120° C. ##STR13## 8.3 g of 2-morpholino-5-formylthiazole and 13.6 g of the compound of the formula ##STR14## were dissolved in 100 ml of methylene. After 100 ml of acetic anhydride had been added, the methylene chloride was distilled off and the temperature was increased to 120° C. After cooling to 100° C. with stirring, the target product precipitated. Following addition of 100 ml of methanol, the mixture was stirred overnight and filtered with suction, and the filter residue was washed with methanol and dried.

Yield: 17.1 g=76% of theory

Melting point: >210° C.

λ_(max) (THF): 531 nm

R_(f) : 0.45 (ethyl acetate)

Example P6 was also followed to synthesize the following dyes: ##STR15## Transfer of the dyes

To be able to test the transfer characteristics of the dyes in a quantitative and simple manner, the heat transfer process was carried out with large hotplates instead of a thermal printing head, the transfer hotplates instead of a thermal printing head, the transfer temperature being varied within the range 70° C.<T<120° C. and the transfer time being set at 2 minutes.

A) General recipe for coating the substrates with dye:

1 g of binder were dissolved in 8 ml (8:2 v/v) of toluene/ethanol at from 40° to 50° C. A solution of 0.25 g of dye with or without assistants in 5 ml of tetrahydrofuran was added by stirring. The print paste thus obtained was applied with an 80 μm knife to a sheet of polyester film (thickness: 6-10 μm) and dried with a hairdrier.

B) Testing of thermal transferability

The dyes used were tested in the following manner:

The polyester sheet donor containing the dye under test in the coated front was placed face down on a sheet of commercial Hitachi Color Video Print Paper (receiver) and pressed down. Donor/receiver were then wrapped in aluminum foil and heated between two hot plates at different temperatures T (within the temperature range 70° C.<T<120° C.). The amount of dye diffusing into the bright plastic layer of the receiver is proportional to the optical density (=absorbance A). The latter was determined photometrically. If the logarithm of the absorbance A of the colored receiver papers measured within the temperature range from 80° to 110° C. is plotted against the corresponding reciprocal of the absolute temperature, the result is a straight line whose slope gives the activation energy ΔE_(T) for the transfer experiment: ##EQU1##

To complete the characterization, it is additionally possible to infer from the plots the temperature T*[C] at which the absorbance A of the colored receiver papers attains the value 1.

The dyes listed in the tables which follow were processed according to A), and the resulting dye-coated substrates were tested in respect of their transfer characteristics according to B). The tables list in some instances the thermal transfer parameters T* and ΔE_(T), the absorption maxima of the dyes λ_(max) (measured in methylene chloride, unless otherwise stated) and the binders used. The weight ratio of dye:binder is always 1:4. In those cases where an assistant is present, the weight ratio of dye:assistant is 1:0.75.

The following abbreviations apply:

B=binder (EC=ethylcellulose, EHEC=ethylhydroxyethylcellulose, AC=cellulose acetobutyrate, M=mixture of polyvinyl butyrate and ethylcellulose in a weight ratio of 2:1)

A=assistant (chol=cholesterol).

                                      TABLE 1                                      __________________________________________________________________________      ##STR16##                                                                      Ex. No.                                                                             A.sup.1                                                                           A.sup.2                                                                              A.sup.3  X  A.sup.4   λ[nm]                                                                       B   A  T* [°C.]                                                                     ##STR17##                 __________________________________________________________________________     1    CH.sub.3                                                                          CH(CH.sub.3).sub.2                                                                   H        N                                                                                  ##STR18##                                                                               610 M   -- 108  15                         2    C.sub.2 H.sub.5                                                                   C.sub.6 H.sub.13                                                                     H        N                                                                                  ##STR19##                                                                               610 M   -- 89   15                         3    C.sub.4 H.sub.9                                                                   C.sub.4 H.sub.9                                                                      CH.sub.3 N                                                                                  ##STR20##                                                                               623 M   -- 90   17                         4    C.sub.2 H.sub.5                                                                   C.sub.4 H.sub.9                                                                      CH.sub.3 N                                                                                  ##STR21##                                                                               621 M   -- 89   16                         5    C.sub.4 H.sub.9                                                                   C.sub.4 H.sub.9                                                                      CH.sub.3 N                                                                                  ##STR22##                                                                               621 M   -- 91   16                         6    C.sub.4 H.sub.9                                                                   C.sub.2 H.sub.4 CN                                                                   H        N                                                                                  ##STR23##                                                                               590 M   -- 111  14                         7    C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                      NHCOCH.sub.3                                                                            N                                                                                  ##STR24##                                                                               619 M   -- 87   19                         8    C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                      NHCOCH.sub.3                                                                            N                                                                                  ##STR25##                                                                               619 M   -- 89   18                         9    C.sub.2 H.sub.5                                                                   C.sub.4 H.sub.9                                                                      NHCOCH.sub.3                                                                            N  C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.4                                      H.sub.9   620 EHEC                                                                               -- 93   18                         10   C.sub.4 H.sub.9                                                                   C.sub.4 H.sub.9                                                                      NHCOCH.sub.3                                                                            N                                                                                  ##STR26##                                                                               623 M   -- 110  15                         11   C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                      NHSO.sub.2 N(CH.sub.3).sub.2                                                            N                                                                                  ##STR27##                                                                               618 M   -- 90   14                         12   C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                      H        CH                                                                                 ##STR28##                                                                               559 M   -- 89   11                         13   CH.sub.3                                                                          CH.sub.3                                                                             H        CH                                                                                 ##STR29##                                                                               554 M   -- 112  16                         14   C.sub.4 H.sub.9                                                                   C.sub.2 H.sub.5                                                                      OCH.sub.3                                                                               CH                                                                                 ##STR30##    AC  Chol                                                                              87   13                         15   C.sub.4 H.sub.9                                                                   C.sub.2 H.sub.5                                                                      OCH.sub.3                                                                               N  C.sub.4 H.sub.8 OC.sub.3 H.sub.7                                                             EC  -- 92   16                         __________________________________________________________________________

                                      TABLE 2                                      __________________________________________________________________________      ##STR31##                                                                      Ex. No.                                                                             A.sup.1                                                                              A.sup.2                                                                              A.sup.3           X  λ[nm]                                                                       B                                                                                A                                                                                T* [°C.]                                                                     ##STR32##                  __________________________________________________________________________     16   C.sub.2 H.sub.5                                                                      C.sub.4 H.sub.9                                                                      C.sub.6 H.sub.5   N  612 M --                                                                               86   16                          17   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                      C.sub.6 H.sub.5   N  615 M --                                                                               82   16                          18   CH(CH.sub.3).sub.2                                                                   CH(CH.sub.3).sub.2                                                                   C.sub.6 H.sub.5   N  617 M --                                                                               90   17                          19   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                       ##STR33##        N  624 M --                                                                               90   13                          20   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                       ##STR34##        N  621 M --                                                                               92   12                          21   C.sub.2 H.sub.5                                                                      C.sub.4 H.sub.9                                                                       ##STR35##        N  612 M --                                                                               84   17                          22   C.sub.2 H.sub.5                                                                      C.sub.4 H.sub.9                                                                       ##STR36##        N  611 M --                                                                               85   16                          23   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                      C.sub.6 H.sub.5   CH 560 M --                                                                               85   12                          24   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub. 5                                                                     Thien-2-yl        CH 579 M --                                                                               90   16                          25   Benzyl                                                                               CH.sub.3                                                                             H                 CH 537 M --                                                                               88    8                          26   C.sub.4 H.sub.9                                                                      C.sub.2 H.sub.5                                                                      C.sub.6 H.sub.5   CH 561 M --                                                                               90   12                          27   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                       ##STR37##        CH 566 M --                                                                               109  10                          __________________________________________________________________________

                                      TABLE 3                                      __________________________________________________________________________      ##STR38##                                                                      Ex. No.                                                                             A.sup.1                                                                               A.sup.3                                                                              X  A.sup.4   λ[nm]                                                                       B  A  T* [°C.]                                                                     ##STR39##                       __________________________________________________________________________     28   C.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                      H     N                                                                                  ##STR40##                                                                               631 M  -- 110  24                               29   C.sub.6 H.sub.13                                                                      H     N                                                                                  ##STR41##                                                                               636 EC Chol                                                                              107  22                               30   C.sub.3 H.sub.7                                                                       CH.sub.3                                                                             N  C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.4 H.sub.9                                        640 EC -- 100  16                               31   C.sub.2 H.sub.5                                                                       H     CH                                                                                 ##STR42##                                                                               --  M  --  98  15                               32   C.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                      CH.sub.3                                                                             CH                                                                                 ##STR43##                                                                               --  EC -- 100  16                               33   H      NHCOCH.sub.3                                                                         N                                                                                  ##STR44##                                                                               616 M  --  98  14                               __________________________________________________________________________

                                      TABLE 4                                      __________________________________________________________________________      ##STR45##                                                                      Ex. No.                                                                             A.sup.1                                                                           A.sup.2                                                                              A.sup.3                                                                              X                                                                                λ[nm]                                                                       B                                                                                A                                                                                T* [°C.]                                                                     ##STR46##                                  __________________________________________________________________________     34   H  CH(CH.sub.3).sub.2                                                                   CH(CH.sub.3).sub.2                                                                   N 608 M --                                                                               101  16                                          35   C.sub.2 H.sub.5                                                                   C.sub.3 H.sub.6 OCH.sub.3                                                            C.sub.3 H.sub.6 OCH.sub.3                                                            N 619 M --                                                                                94  17                                          __________________________________________________________________________

                  TABLE 5                                                          ______________________________________                                          ##STR47##                                                                       No. Ex.                                                                            Y      A.sup.3                                                                               X    λ[nm]                                                                         B   A   T*[°C.]                                                                       ##STR48##                         ______________________________________                                         36   CH.sub.2                                                                              C.sub.6 H.sub.5                                                                       N    616   M   --  90    14                                 37   O      C.sub.6 H.sub.5                                                                       N    612   M   --  92    15                                 38   O      H      CH   537   M   --  87    13                                 ______________________________________                                    

                                      TABLE 6                                      __________________________________________________________________________      ##STR49##                                                                       No. Ex.                                                                          A.sup.1                                                                           A.sup.2                                                                           A.sup.3                                                                              X  A.sup.4        λ[nm]                                                                       B  A  T*[ °C.]                                                                    ##STR50##                      __________________________________________________________________________     39 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                   NHCOCH.sub.3                                                                         N                                                                                  ##STR51##     593 EC -- 129 15                              40 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub. 5                                                                  NHCOCH.sub.3                                                                         N                                                                                  ##STR52##     593 EC -- 121 13                              41 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                   OCH.sub.3                                                                            N                                                                                  ##STR53##     570 EC -- 127 10                              42 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                   OCH.sub.3                                                                            N                                                                                  ##STR54##     570 EC -- 117 10                              43 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                   H     CH C.sub.6 H.sub.13                                                                              528 M  --  78 14                              __________________________________________________________________________

                                      TABLE 7                                      __________________________________________________________________________      ##STR55##                                                                       No. Ex.                                                                          A.sup.1                                                                           A.sup.2  A.sup.3    X  A.sup.4                                                                               λ[nm]                                                                      B  A  [°C.]T*                                                                    ##STR56##                     __________________________________________________________________________     44 C.sub.3 H.sub.7                                                                   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                             2-Thienyl  N  C.sub.2 H.sub.4 OCH.sub.3                                                             626*                                                                              EC -- 100                                                                               14                             45 C.sub.2 H.sub.5                                                                   (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                               C.sub.6 H.sub.5                                                                           N  C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                      584*                                                                              M  -- 94 13                             46 C.sub.3 H.sub.7                                                                   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                             2-Thienyl  N  C.sub.3 H.sub.6 OCH.sub.3                                                             624*                                                                              M  -- 98 12                             47 C.sub.2 H.sub.5                                                                   (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                               C.sub.6 H.sub.5                                                                           N  C.sub.2 H.sub.4 OCH.sub.3                                                             584*                                                                              EC -- 94 14                             48 C.sub.2 H.sub.5                                                                   (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                               C.sub.6 H.sub.5                                                                           N  C.sub.3 H.sub.6 OCH.sub.3                                                             584*                                                                              M  -- 96 13                             49 C.sub.2 H.sub.5                                                                   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                             C.sub.6 H.sub.5                                                                           N  C.sub.2 H.sub.4 OCH.sub.3                                                             585*                                                                              M  -- 97 14                             50 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                         C.sub.6 H.sub.5                                                                           CH C.sub.2 H.sub.4 OCH.sub.3                                                             534                                                                               M  -- 91 13                             51 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                          ##STR57## CH C.sub.6 H.sub.13                                                                      537                                                                               M  -- 84 18                             52 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                         Thien-2-y  CH C.sub.6 H.sub.13                                                                      551                                                                               M  -- 88 19                             __________________________________________________________________________      *λ.sub.max was measured in THF                                    

                  TABLE 8                                                          ______________________________________                                          ##STR58##                                                                      Ex. No.                                                                                λ[nm]                                                                            B      A    T* [°C.]                                                                        ##STR59##                                ______________________________________                                         53      590      M      --   99      12                                        ______________________________________                                    

Similar results are obtained with the dyes listed in Table 9. (The roman numerals under D refer to the abovementioned radicals of the formula II).

                                      TABLE 9                                      __________________________________________________________________________      ##STR60##                                                                     Ex. No.                                                                              D   X   L.sup.2 R.sup.1     L.sup.3                                                                               R.sup.5                                                                               R.sup.6                                                                               Hue                     __________________________________________________________________________     54    IIa CH  C.sub.4 H.sub.9                                                                         ##STR61##  C.sub.2 H.sub.5                                                                       H      H      Magenta violet          55    IIa CH  C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.5                                                                            C.sub.3 H.sub.7                                                                       H      H      Magenta violet          56    IIa CH  C.sub.2 H.sub.4 CO.sub.2 C.sub.2 H.sub.5                                               C.sub.4 H.sub.8 OCH.sub.3                                                                  C.sub.2 H.sub.5                                                                       H      H      Magenta                 57    IIa CH  C.sub.2 H.sub.5                                                                        C.sub.3 H.sub.6 OC.sub.4 H.sub.9                                                           C.sub.2 H.sub.5                                                                       H      CH.sub.3                                                                              Magenta violet          58    IIa CH  CH(CH.sub.3).sub.2                                                                      ##STR62##  CH(CH.sub.3).sub.2                                                                    H      OCH.sub.3                                                                             Magenta violet          59    IIa CH  C.sub.4 H.sub.9                                                                         ##STR63##  C.sub.2 H.sub.5                                                                       H      CH.sub.3                                                                              Magenta violet          60    IIa CH  C.sub.4 H.sub.9                                                                        C.sub.7 H.sub.15                                                                           C.sub.2 H.sub.5                                                                       H      NHCOCH.sub.3                                                                          Magenta violet          61    IIa CH  C.sub.3 H.sub.7                                                                        (CH.sub.2).sub.2 CO.sub.2 C.sub.4 H.sub.9                                                  C.sub.3 H.sub.6 OCH.sub.3                                                             H      H      Magenta                 62    IIa N   C.sub.4 H.sub.9                                                                        (CH.sub.2).sub.2 CO.sub.2 C.sub.4 H.sub.9                                                  C.sub.4 H.sub.9                                                                       H      H      Cyan                    63    IIa N   C.sub.2 H.sub.5                                                                        C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OCH.sub.3                                                 C.sub.2 H.sub.5                                                                       H      C.sub.2 H.sub.5                                                                       Cyan                    64    IIa N   C.sub.2 H.sub.5                                                                         ##STR64##  C.sub.3 H.sub.7                                                                       H      CH.sub.3                                                                              Cyan                    65    IIa N   CH(CH.sub.3).sub.2                                                                     (CH.sub.2).sub.4 OC.sub.3 H.sub.7                                                          C.sub.2 H.sub.5                                                                       H      C.sub.2 H.sub.5                                                                       Cyan                    66    IIa N   C.sub.4 H.sub.9                                                                         ##STR65##  C.sub.2 H.sub.5                                                                       H      NHCOCH.sub.3                                                                          Cyan                    67    IIa N   C.sub.3 H.sub.7                                                                         ##STR66##  C.sub.2 H.sub.5                                                                       H      NHSO.sub.2 C.sub.4                                                             H.sub.9                                                                               Cyan                    68    IIa N   C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                           C.sub.7 H.sub.15                                                                      H      NHSO.sub.2 C.sub.2                                                             H.sub.5                                                                               Cyan                    69    IIa N   H                                                                                       ##STR67##  C.sub.4 H.sub.9                                                                       OCH.sub.3                                                                             CH.sub.3                                                                              Cyan                    70    IIa N   C.sub.2 H.sub.4 CN                                                                     (CH.sub.2).sub.2 OC.sub.6 H.sub.13                                                         C.sub.4 H.sub.9                                                                       H      CH.sub.3                                                                              Cyan                    71    IIa N   H                                                                                       ##STR68##  C.sub.5 H.sub.11                                                                      OC.sub.2 H.sub.5                                                                      CH.sub.3                                                                              Cyan                    72    IIb CH  C.sub.2 H.sub.5                                                                         ##STR69##  --     --     H      Magenta                 __________________________________________________________________________                                                            violet                  Ex. No.                                                                              D   X   L.sup.2 R.sup.1     L.sup.4                                                                               R.sup.6                                                                               R.sup.5                                                                               Hue                     __________________________________________________________________________     73    IIb CH  C.sub.4 H.sub.9                                                                        (CH.sub.2).sub.4 OC.sub.4 H.sub.9                                                          --     --     H      violet                  74    IIb N   C.sub.2 H.sub.5                                                                         ##STR70##  --     --     H      Cyan                    75    IIc CH  C.sub.4 H.sub.9                                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                  --     --     H      Magenta violet          76    IIc CH  C.sub.3 H.sub.6 OC.sub.4 H.sub.9                                                        ##STR71##  --     --     H      Magenta violet          77    IIc CH  C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                  --     --     H      Magenta violet          78    IIc CH  C.sub.2 H.sub.5                                                                        C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.6 H.sub.5                                          --     --     CH.sub.3                                                                              violet                  79    IIc CH  C.sub.4 H.sub.9                                                                        (CH.sub.2).sub.2 CO.sub.2 C.sub.5 H.sub.11                                                 --     --     OCH.sub.3                                                                             violet                  80    IIc CH  C.sub.2 H.sub.5                                                                        (CH.sub.2).sub.2 OC.sub.5 H.sub.11                                                         --     --     C.sub.2 H.sub.5                                                                       violet                  81    IIc CH  C.sub.2 H.sub.4 CN                                                                     (CH.sub.2).sub.2 OC.sub.5 H.sub.11                                                         --     --     H      Magenta                 82    IIc CH  C.sub.2 H.sub.4 OH                                                                     (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                  --     --     CH.sub.3                                                                              Magenta                 83    IIc CH  C.sub.2 H.sub.4 CO.sub.2 C.sub.2 H.sub.5                                               (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                  --     --     H      Magenta                 84    IIc N   (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                               ##STR72##  --     --     H      Cyan                    85    IIc N   C.sub.2 H.sub.5                                                                        (CH.sub.2).sub.4 OC.sub.3 H.sub.6 OC.sub.2 H.sub.5                                         --     --     CH.sub.3                                                                              Cyan Turquoise          86    IIc N   C.sub.4 H.sub.9                                                                        CH.sub.3    --     --     H      Cyan                    87    IIc N   H       C.sub.4 H.sub.8 OC.sub.3 H.sub.6 OC.sub.4 H.sub.9                                          --     --     CH.sub.3                                                                              Cyan                    88    IIc N   C.sub.3 H.sub.7                                                                         ##STR73##  --     --     NHCOCH.sub.3                                                                          Cyan Turquoise          89    IIc N   C.sub.2 H.sub.4 CN                                                                     C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.4 H.sub.9                                          --     --     CH.sub.3                                                                              Cyan                    90    IIc N   C.sub.3 H.sub.6                                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                  --     --     H      Cyan                    91    IIc N   C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.4 CO.sub.2 C.sub.7 H.sub.15                                                  --     --     CH.sub.3                                                                              Cyan Turquoise          92    IIc N   C.sub.2 H.sub.4 OH                                                                     C.sub.3 H.sub.6 OC.sub.3 H.sub.6 OC.sub.2 H.sub.5                                          --     --     H      Cyan                    93    IId CH  --                                                                                      ##STR74##  --     H      H      Yellow                  94    IId CH  --      C.sub.3 H.sub.6 OC.sub.4 H.sub.9                                                           --     m-CH.sub.3                                                                            OC.sub.2 H.sub.5                                                                      Yellow                  95    IId CH  --                                                                                      ##STR75##  --     m-CO.sub.2 C.sub.6 H.sub.13                                                           H      Yellow                  __________________________________________________________________________      ##STR76##                                                                     Ex. No.                                                                              D   X   L.sup.2 R.sup.1     L.sup.3                                                                               R6     R.sup.5                                                                               Hue                     __________________________________________________________________________     96    IIe CH  C.sub.3 H.sub.6 OC.sub.4 H.sub.9                                                        ##STR77##  --     --     CH.sub.3                                                                              Magenta violet          97    IIe N   C.sub.3 H.sub.7                                                                         ##STR78##  --     --     H      Cyan Turquoise          98    IIe N                                                                                   ##STR79##                                                                              ##STR80##  --     --     CH.sub.3                                                                              Turquoise               99    IIg CH  --                                                                                      ##STR81##  --     --     H      Magenta violet          100   IIg CH  --      C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.6 H.sub.5                                          --     --     CH.sub.3                                                                              violet                  101   IIg N   --      C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.4 H.sub.9                                          --     --     H      Cyan                    102   IIg N   --                                                                                      ##STR82##  --     --     CH.sub.3                                                                              Cyan Turquoise          103   IIg N   --      C.sub.3 H.sub.6 OC.sub.3 H.sub.7                                                           --     --     NHCOCH.sub.3                                                                          Cyan                    __________________________________________________________________________                                                            Turquoise          

                                      TABLE 10                                     __________________________________________________________________________      ##STR83##                                                                       No.Ex.                                                                           A.sup.1    A.sup.2                                                                                A.sup.3   X  A.sup.4                                                                               λ[mm]                                                                       B   A                                                                                T*[°C.]                                                                     ##STR84##             __________________________________________________________________________     104                                                                               CH(CH.sub.3).sub.2                                                                        C.sub.2 H.sub.5                                                                        CH.sub.3  N                                                                                  ##STR85##                                                                            621 EHEC                                                                               --                                                                               96  12                     105                                                                               C.sub.3 H.sub.7                                                                           C.sub.2 H.sub.5                                                                        CH.sub.3  N                                                                                  ##STR86##                                                                            621 EHEC                                                                               --                                                                               111 14                     106                                                                               C.sub.4 H.sub.9                                                                           C.sub.4 H.sub.9                                                                        NHCOC.sub.3 H.sub.7                                                                      N                                                                                  ##STR87##                                                                            625 EHEC                                                                               --                                                                               105 10                     107                                                                                ##STR88## C.sub.2 H.sub.5                                                                        H         CH                                                                                 ##STR89##                                                                            555 EHEC                                                                               --                                                                               100  9                     108                                                                               C.sub.2 H.sub.4 OCOCH.sub.2 OCH.sub.3                                                     C.sub.2 H.sub.5                                                                        H         N                                                                                  ##STR90##                                                                            601 M   --                                                                               87  10                     109                                                                               C.sub.2 H.sub.4 Cl                                                                        C.sub.2 H.sub.5                                                                        H         N                                                                                  ##STR91##                                                                            595 M   --                                                                               84   9                     110                                                                               C.sub.2 H.sub.5                                                                           C.sub.2 H.sub.5                                                                        NHCO.sub.2 C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                              N                                                                                  ##STR92##                                                                            616 M   --                                                                               76  10                     111                                                                                ##STR93## C.sub.2 H.sub.5                                                                        H         N                                                                                  ##STR94##                                                                            604 M   --                                                                               76   8                     112                                                                               C.sub.2 H.sub.4 OCOCH.sub.3                                                               C.sub.2 H.sub.5                                                                        H         N                                                                                  ##STR95##                                                                            604 EHEC                                                                               --                                                                               104 10                     113                                                                                ##STR96## C.sub.2 H.sub.5                                                                        CH.sub.3  N                                                                                  ##STR97##                                                                            618 M   --                                                                               78  10                     114                                                                               C.sub.4 H.sub.9                                                                           C.sub.2 H.sub.5                                                                        CH.sub.3  N                                                                                  ##STR98##                                                                            618 M   --                                                                               94  11                     115                                                                               C.sub.4 H.sub.9                                                                           C.sub.4 H.sub.9                                                                        CH.sub.3  N                                                                                  ##STR99##                                                                            621 M   --                                                                               94  11                     116                                                                                ##STR100##                                                                               C.sub.2 H.sub.5                                                                        CH.sub.3  N                                                                                  ##STR101##                                                                           618 M   --                                                                               80   8                     117                                                                               C.sub.4 H.sub.9                                                                           C.sub.4 H.sub.9                                                                        H         N  C.sub.3 H.sub.7                                                                       616 M   --                                                                               73   7                     118                                                                               C.sub.2 H.sub.5                                                                           C.sub.2 H.sub.5                                                                        OCH(CH.sub.3).sub.2                                                                      N                                                                                  ##STR102##                                                                           601 M   --                                                                               82   9                     119                                                                               CH.sub.3   CH.sub.3                                                                               H         CH                                                                                 ##STR103##                                                                           554 M   --                                                                               112 16                     120                                                                               C.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                          C.sub.2 H.sub.5                                                                        H         N                                                                                  ##STR104##                                                                           615 M   --                                                                               109 11                     121                                                                               C.sub.2 H.sub.4 CN                                                                        C.sub.4 H.sub.9                                                                        H         N                                                                                  ##STR105##                                                                           590 M   --                                                                               111 13                     122                                                                               C.sub.4 H.sub.9                                                                           C.sub.4 H.sub.9                                                                        H         N                                                                                  ##STR106##                                                                           620 M   --                                                                               110 12                     123                                                                               C.sub.4 H.sub.9                                                                           C.sub.2 H.sub.5                                                                        CH.sub.3  N                                                                                  ##STR107##                                                                           621 M   --                                                                               117 16                     124                                                                               C.sub.4 H.sub.9                                                                           C.sub.2 H.sub.5                                                                        CH.sub.3  N  CH.sub.3                                                                              619 M   --                                                                               85   9                     125                                                                               C.sub.4 H.sub.9                                                                           C.sub.4 H.sub.9                                                                        CH.sub.3  N  C.sub.2 H.sub.5                                                                       619 M   --                                                                               83  10                     126                                                                               C.sub.4 H.sub.9                                                                           C.sub.2 H.sub.5                                                                        CH.sub.3  N  C.sub.2 H.sub.5                                                                       621 M   --                                                                               119 13                     127                                                                               C.sub.4 H.sub.9                                                                           C.sub.4 H.sub.9                                                                        CH.sub.3  N                                                                                  ##STR108##                                                                           625 M   --                                                                               88  12                     128                                                                               C.sub.4 H.sub.9                                                                           C.sub.4 H.sub.9                                                                        CH.sub.3  N  CH.sub.3                                                                              621 M   --                                                                               108 10                     129                                                                               C.sub.4 H.sub.9                                                                           CH.sub.3                                                                               H         N                                                                                  ##STR109##                                                                           607 M   --                                                                               82   9                     130                                                                               C.sub.2 H.sub.5                                                                           C.sub.2 H.sub.5                                                                        CH.sub.3  N                                                                                  ##STR110##                                                                           615 M   --                                                                               83  11                     131                                                                               (CH.sub.2).sub.2 CH(CH.sub.3).sub.2                                                       C.sub.2 H.sub.5                                                                        CH.sub.3  N                                                                                  ##STR111##                                                                           620 EHEC                                                                               --                                                                               92  13                     132                                                                               C.sub.2 H.sub.4 CH(CH.sub.3).sub.2                                                        C.sub.2 H.sub.5                                                                        CH.sub.3  N  C(CH.sub.3).sub.3                                                                     621 M   --                                                                               102  8                     133                                                                               CH.sub.2 CH(CH.sub.3).sub.2                                                               C.sub.4 H.sub.9                                                                        H         N  C(CH.sub.3).sub.3                                                                     615 M   --                                                                               83  11                     134                                                                               C.sub.4 H.sub.9                                                                           C.sub.4 H.sub.9                                                                        OCH.sub.3 N                                                                                  ##STR112##                                                                           603 M   --                                                                               98   6                     135                                                                               C.sub.2 H.sub.4 OCONHC.sub.4 H.sub.9                                                      C.sub.2 H.sub.5                                                                        H         N                                                                                  ##STR113##                                                                           596 M   --                                                                               97  16                     136                                                                               C.sub.2 H.sub.5                                                                           C.sub.2 H.sub.5                                                                        H         N                                                                                  ##STR114##                                                                           608 M   --                                                                               97  14                     137                                                                               C.sub.2 H.sub.5                                                                           C.sub.2 H.sub.5                                                                        NHCOCH.sub.2 OCH.sub.3                                                                   N                                                                                  ##STR115##                                                                           622 M   --                                                                               93   8                     138                                                                               C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                          C.sub.2 H.sub.5                                                                        NHCOCH.sub.3                                                                             N                                                                                  ##STR116##                                                                           623 M   --                                                                               88   8                     139                                                                               C.sub.2 H.sub.5                                                                           C.sub.2 H.sub.5                                                                         ##STR117##                                                                              N                                                                                  ##STR118##                                                                           624 M   --                                                                               81   8                     140                                                                               C.sub.2 H.sub.4 O.sub.2 CCH.sub.3                                                         C.sub.2 H.sub.4 O.sub.2 CH.sub.3                                                       NHCOCH.sub.2 OCH.sub.3                                                                   N                                                                                  ##STR119##                                                                           615 M   --                                                                               82   8                     141                                                                               C.sub.2 H.sub.4 O.sub.2 CC.sub.2 H.sub.5                                                  C.sub.2 H.sub.4 O.sub.2 CC.sub.2 H.sub.5                                               NHCOC.sub.2 H.sub.5                                                                      N                                                                                  ##STR120##                                                                           616 M   --                                                                               83  10                     __________________________________________________________________________

                                      TABLE 11                                     __________________________________________________________________________      ##STR121##                                                                     Ex. No.                                                                              A.sup.1                                                                            A.sup.2                                                                            A.sup.3            X   A.sup.4                                                                              λ[mm]                                                                       B                                                                                A                                                                                T* [°C.]                                                                     ##STR122##            __________________________________________________________________________     142   C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.5                                                                     ##STR123##        CH                                                                                  ##STR124##                                                                          563 M --                                                                               155   3                     143   C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.5                                                                     ##STR125##        N                                                                                   ##STR126##                                                                          623 M --                                                                               101  10                     __________________________________________________________________________

                                      TABLE 12                                     __________________________________________________________________________      ##STR127##                                                                    Ex.                                                                            No.                                                                               D  X  L.sup.2                                                                           R.sup.1                                                                              L.sup.3                                                                            Y    R.sup.5                                                                          R.sup.6                                                                          R.sup.8                                                                            λ.sub.max (nm)                       __________________________________________________________________________     144                                                                               IIa                                                                               N  CH.sub.3                                                                           ##STR128##                                                                          CH.sub.3                                                                           CO.sub.2 C.sub.4 H.sub.9                                                            H H --  680                                         145                                                                               IIa                                                                               CH C.sub.2 H.sub.5                                                                    ##STR129##                                                                          C.sub.4 H.sub.9                                                                    CO.sub.2 C.sub.4 H.sub.9                                                            H H --  638                                         146                                                                               IIk                                                                               CH C.sub.2 H.sub.5                                                                    ##STR130##                                                                          C.sub.2 H.sub.5                                                                    CN   --                                                                               --                                                                               C.sub.6 H.sub.5                                                                    636                                         147                                                                               IIk                                                                               CH C.sub.2 H.sub.5                                                                    ##STR131##                                                                          C.sub.2 H.sub.5                                                                    CN   --                                                                               --                                                                                ##STR132##                                                                        620                                         __________________________________________________________________________ 

We claim:
 1. A process for transferring a methine dye from a transfer to plastic-coated paper comprising treating with an energy source a transfer on which there is or are situated one or more dyes of the formula I and/or Ia ##STR133## where R¹ is C₁ -C₂₀ -alkyl, which may be substituted and interrupted by one or more oxygen atoms, or is substituted or unsubstituted phenyl or hydroxyl,R² is a 5- or 6-membered carbocyclic or heterocyclic ring which may be substituted and benzofused, R³ is cyano, carbamoyl, carboxyl or C₁ -C₄ alkoxycarbonyl, R⁴ is oxygen or a radical of the formula ##STR134## where L¹ is in each case C₁ -C₈ -alkyl which may be interrupted by 1 or 2 oxygen atoms, and X is CH or nitrogen.
 2. A transfer, suitable for a thermal transfer printing process, comprising: a binder and one or more dyes of the formula I and/or Ia ##STR135## where R¹ is C₁ -C₂₀ -alkyl, which may be substituted and interrupted by one or more oxygen atoms, or is substituted or unsubstituted phenyl or hydroxyl,R² is 5- or 6-membered carbocyclic or heterocyclic ring which may be substituted and benzofused, R³ is cyano, carbamoyl, carboxyl or C₁ C₄ -alkoxycarbonyl, R⁴ is oxygen or a radical of the formula ##STR136## where L¹ is in each case C₁ -C₄ -alkyl which may be interrupted by 1 or 2 oxygen atoms, and X is CH or nitrogen. 